How is this related to TianoCore¶
As you can probably tell, Project Mu is based on TianoCore. It represents a variant of TianoCore that was customized within Microsoft for scaling and maintainability. It's not exactly a staging branch for TianoCore, as there are some changes that may not have application within or meet the explicit goals of that project, but it is a place where features and changes can be publicly featured and discussed.
So, is this a fork¶
Not entirely. It is our goal to continue to treat TianoCore as a true upstream. Our release branches will always be based on the latest stable TianoCore release, and we will always try to PR viable fixes and features into the TianoCore project.
What is it? Where is it going¶
Project Mu is a product of the Microsoft Core UEFI team and is the basis for the system firmware within a number of Microsoft products. It will continue to be maintained to reflect the FW practices and features leveraged for the best experience with Windows and other Microsoft products.
A secondary purpose is to engage with the community, both in TianoCore and the industry at large. We hope that Project Mu serves as a concrete example for discussing different approaches to managing the challenges faced by the UEFI ecosystem.
Is this really following "Less is More"¶
Yes. The idea is lowering the entanglement of code, lowering the coupling, and allowing the product to pick and choose the code it needs. This means when building any given product, you don't need all the Project Mu code.
Why are there so many repos¶
Project Mu makes liberal use of multiple repositories due to the mixture of requirements in the UEFI ecosystem. Some repos are split for technical reasons, some for organizational, and some for legal.
For details, see "Repo Philosophy" in What and Why.